The invention relates to a tracking system and more specifically to one that may be used to accurately point a solar collector at the sun throughout the day.
Present day solar collector tracking systems usually employ two independent drives to tilt the collector about two axes. One axis is the elevation axis, whereby the collector is tilted within an angular range of about ninety degrees between "looking at the horizon" and "looking straight up". The other axis is vertical, commonly called "azimuth". A typical day starts with the azimuth drive pointing the collector east and ends with it pointing west. The required range of angular rotation depends on the earth's latitude at which the solar collector is installed. In the tropics the angular rotation needs more than 360 degrees.
The prior art solar collector tracking systems generally use electric drives having high ratio gear reducers to turn the collector in the direction of the sun. Often, the angle that the collector is pointing is calculated by counting the turns of the electric motor (from a 0 reference point signaled by another switch). Error in the gear reducers or linkage between the motor and collector, such as backlash and non-linearly, detracted from the accuracy. When high accuracy was required, the gear reducers were very expensive.
Prior art drives have been known to be broken by high winds and dust devils. Thus the solar collector tracking systems normally require that the collector be capable of going into wind stow position to avoid damage when winds exceed those required by building codes. "Wind stow" is an attitude of the collector that presents the smallest area to the wind. Generally, a wind sensor will trigger a command for the elevation actuator to point the collector straight up. Prior art electric elevation actuators with high ratio speed reducers are very slow to put the collector into wind stow, sometimes taking as long as forty-five minutes.
It is an object of the invention to provide a novel solar collector tracking system that eliminates the need for electric drives having expensive high ratio gear reducers to turn the collector in the direction of the sun.
It is another object of the invention to provide a novel solar collector tracking system that dramatically reduces wind stow time for the solar collector when compared to the amount of time required by present day solar collector tracking systems that utilize electric drives and high ratio gear reducers.
It is also an object of the invention to provide a novel solar collector tracking system that utilizes hydraulic actuators powered by a hydraulic power unit that receives its directions from an electronic controller that monitors the azimuth angles and elevation angles of a solar collector panel.
It is an additional object of the invention to provide a novel solar collector tracking system that utilizes an accumulator in its hydraulic power unit that eliminates the starting and stopping of a motor and pump every few seconds to produce the required sun tracking for the solar collector.
It is a further object of the invention to provide a novel solar collector tracking system that is more economical and easier to manufacture than present day solar collector tracking systems that utilize electric drives having high ratio gear reducers to turn the collector in the direction of the sun.